1. Program Compilation and Execution

2. Today’s Objectives Explain why runtime stack needed for C
Draw logical division of memory into stack, heap
Compare and contrast stack and heap
List variables stored in heap; stack; neither

3. Logical Memory Layout Stack Heap Static Space D Y N A M I C
Currently not in use
Currently not in use
Heap
Static Space

4. Dice.c int NUM = 100000; main() { int i, roll, *counts;
counts = (int *) malloc (13 * sizeof(int));
for (i = 0; i < 13; i++) counts[i] = 0;
for ( i = 0; i < NUM; i++)
roll = rand() % 6 + rand() %6 + 2
counts[roll]++;
for (i = 2; i < 13; i++)
printf(“There were %d rolls of %d\n”,
counts[i],i); }

5. Where Are the Variables?
Stack D Y N A M I C
i; roll; counts
Currently not in use
Currently not in use
Space for 13 ints – pointed to by counts
Heap
Num
“There were %d rolls of %d\n”
Static Space

6. Runtime Stack Activation record for Hanoi; 1 2 3 1
Activation Record for Main
Activation record for main